Operator consoles intended, for example, for customer operated cash dispensers, with which a customer identifies himself as being authorized to withdraw a given sum of money by presenting an appropriate card, are known to the art. The dispenser receives, via the card, information stored in a magnetic medium in the card (customer data) and also, through the keyboard, information concerning the personal code of the customer (PIN-code). The customer data and PIN-code are evaluated in the logical unit of the dispenser and the result of this evaluation is decisive of whether or not the customer is entitled to receive cash through the dispenser. There is a general risk with such systems that unauthorized knowledge of the evaluation of customer data and PIN-code can be used to unlawful ends.
In known consoles of this kind the keyboard and logical unit, which incorporates the necessary algorithms and codes (ciphers) for carrying out the evaluation, are combined to form a single unit which, in order to be accessible to customers, is placed in an open location and not, as would be desirable from the aspect of safety, in a safety box. Consoles of the aforesaid kind may suffer one or more of the following drawbacks:
1. The console is equipped with a protective device which cuts-off the supply voltage in the event of a forced entry (burglary) but does not destroy the content of the memory in the logical unit.
2. The logical unit is not protected, by being located in a safety box or cabinet.
3. It is possible to intercept, or "eaves-drop" on PIN-codes sent from the keyboard to the logical unit.
4. Requisite programmes and codes are incorporated during manufacture of the console, which places high security demands on the prevention of unauthorized acquisition of manufacturing data, in order not to render the system vulnerable.
The object of the invention is to eliminate these drawbacks and similar disadvantages.